CHICAGO -- Two seasons ago, the Los Angeles Kings went on an unprecedented march to the Stanley Cup, marauding past teams despite being the No. 8 seed in the Western Conference.

It would have been hard for this postseason to play out more differently than the one in 2012, but the Kings are four victories away from the same result.

Los Angeles had to rally three times Sunday night to eventually defeat the defending Stanley Cup champion Chicago Blackhawks, 5-4, in overtime of Game 7 at United Center in an incredible finish to a classic Western Conference Final.

Alec Martinez scored 5:47 into overtime for the Kings. Two years after becoming the first team to take a 3-0 lead in every series, despite starting all four on the road, the Kings became the first team in NHL history to play all 21 possible games in the first three rounds. They're also first to win three Game 7s on the road in one postseason.

With the Game 7 win against Chicago, Los Angeles advanced to play the New York Rangers in the Stanley Cup Final. Game 1 will take place Wednesday at Staples Center (8 p.m. ET; NBC, CBC, RDS).

"This series, and I can only speak for myself, was probably the most emotional seven games I've ever played," Kings captain Dustin Brown said. "One, the caliber of the two teams and also how the games were won and lost on both sides. Leads, third-period leads, leads early, leads late ... it was emotional."

Martinez's shot from the left point hit Chicago defenseman Nick Leddy and knuckled past goaltender Corey Crawford. Justin Williams, who tied the NHL record for most goals in Game 7s with his seventh such score earlier in the game, established a new mark for most points in these situations with 14 after setting up Martinez's goal.

"The legend continues," Jarret Stoll said of Williams. "We were giving it to him pretty good already. He's just a special player. He rises to the occasion every big game, every game. He's a leader in every aspect of the game, in the dressing room."

For Chicago, the bid to become the first repeat champions in the NHL since the Detroit Red Wings in 1998 came up five wins short, and in agonizing fashion. The Blackhawks did not roll through the regular season like they did in 2012-13, but Chicago dispatched the St. Louis Blues and Minnesota Wild to reach the conference final for the second straight year and fourth time in six seasons.

The Blackhawks were trying to become the first team in NHL history to rally from a 3-1 deficit to win a series in consecutive postseasons. Chicago is now 1-12 in series when losing three of the first four games. The only time the Blackhawks have advanced was in the second round of 2013, when they won three straight against Detroit.

Chicago blew nine leads in this series, including the three in Game 7.

"It's tough," said Patrick Sharp, who scored twice for the Blackhawks. "It stings right now, that's for sure. Don't really know what else to say other than that. I thought we had a heck of a game tonight. Just one goal short."

Marian Gaborik scored his NHL-leading 12th goal of this postseason with 7:17 left in the third period to even the score at 4-4 and force overtime. Dustin Brown carried the puck into the Chicago zone and drifted to his right to create some space before snapping a shot on goal.

Gaborik was there at the edge of the crease to backhand the rebound into the net and rally the Kings from a deficit for the third time in the game.

"The series, it was up and down, it was emphatic, it was very emotional," Williams said. "Having game-breakers on the team certainly helped us. [Gaborik] getting that goal, [Brown] doing a lot of good work. He had a heck of a game, had a lot of shots, was tenacious around the net. Just having a game-breaker on our team like that really allowed us to tie the game and ultimately win. [Gaborik] has been such a huge piece of this puzzle so far. He wants that Cup just as bad as we do."

After a wild first period, Kings rookie Tyler Toffoli tied the game at 3-3 midway through the second period with his seventh goal of the postseason. Sharp's second goal of the night put Chicago back in front with 1:35 left in the second.

There were goals aplenty in the opening 20 minutes.

Brandon Saad put the Blackhawks on the board first at 5:06. He snapped a shot from the goal line to the left of the net that banked off goaltender Jonathan Quick and across the goal line for his sixth goal of the postseason.

Jonathan Toews gave Chicago a two-goal lead at 8:36 on the power play. Defenseman Brent Seabrook's shot from the right point hit Patrick Kane in front of Quick and went right to Toews at the edge of the crease for an easy tap-in.

It was Toews' team-leading ninth goal of the postseason, and the second assist of the game for Kane, who had nine points in the final three games of this series and led the Blackhawks with 20 points in the playoffs.

Los Angeles scored twice in less than a minute later in the period to erase the two-goal advantage. Jeff Carter batted the rebound of a Brown shot out of the air at the edge of the crease for his ninth goal of the postseason at 16:31.

Williams, who has been dubbed "Mr. Game 7" for his performances in these situations, leveled the score at 17:22. Slava Voynov's shot from the right point never made it to Crawford, and Williams was in the slot for the rebound.

Chicago went back ahead on Sharp's first goal of the evening 12 seconds later. Sharp carried the puck along the right wall and sent a shot toward Quick that skipped off the ice and hopped past the befuddled goaltender at 17:34.

While the Blackhawks will rue being one shot from consecutive Cup Final appearances, this group will be back among the title contenders next season. Every key contributor is under contract, and young players like Teuvo Teravainen and Jeremy Morin could provide significant contributions.

"There's no consolation for a loss like that," Toews said. "What can you say? We have a heck of a group in there. It's tough to lose. It's hard to admit to ourselves this season is over. Not a good feeling especially given the circumstances, how hard we fought, how badly we wanted to win this year. It's impressive. Top to bottom, we've got a lot of talent. I think we've got more character than anything. I could go on and on about that all day. Tough way to go down."

For the Kings, it is time to "reset" one more time, as coach Darryl Sutter called it. Los Angeles has survived an incredible gauntlet to reach this point, not only in number of games, but the quality of the three opponents. The Kings rallied from a 3-0 series hole to beat the San Jose Sharks in the opening round and a 3-2 deficit against the Anaheim Ducks.

The final challenge will be all-world goaltender Henrik Lundqvist and the speedy Rangers, who will certainly be the more rested team early in the series.

"It's kind of hard to put everything into words right now," Anze Kopitar said. "Deep down, we definitely felt we could do this. Coming from behind the whole game, being in a loud rink. Chicago's playing good. To get it done really shows the character we have in this room and that really is priceless."